- 期刊
二體酸系共聚酯之光譜分析
Spectroscopic Analysis of Dimer Acid-based Coppolyesters
摘要
本研究將4,4'-聯萃二甲酸二甲酯，二體酸與烷撐二醇如乙二醇，1,3-丙二醇，1,4-丁二醇，1,5-戌二醇或1,6-己二醇以熔融聚縮合法製得二體酸系共聚酯。單體及所得共聚酯的IR光譜以FT-IR測得。在聚合之後，共聚酯不再出現二體酸及烷撐二醇的OH吸收峰，顯示酯化及酯交換反應已完成。共聚酯的IR特性吸收峰為3066，2926與2855cm^(-1)（C-H伸縮），1708 cm^(-1)（C=O伸縮）及1608與1559cm^(-1)（芳香環）。共聚酯在1608cm^(-1)的芳香峰吸收度與在1708cm^(-1)的C=O峰吸收度的比值隨著p，p'-聯苯二甲酸二甲酯的莫耳含量的增加而增高。因此，IR光譜可定性的指出共聚酯的組成。所得共聚酯亦以質子NMR分析描述之。由NMR光譜分析可得知共聚酯的聚合體組成莫耳比。而有些共聚酯的順序分佈可由NMR光譜看出。共聚酯的雜亂度為1，顯示由熔融聚縮合法所得的共聚酯為雜亂共聚合體。
並列摘要
Various dimer acid-based copolyesters were prepared by melt polycondensation of dimethyl-4,4'-bibenzoate, dimer acid, and an alkylene glycol such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, or 1,6-hexanediol. The IR spectra of the monomers and the copolyesters were determined by FT-IR. The broad O-H absorption peaks (dimer acid and alkylene glycol) were found to disappear after polymerization for the copolyesters indicating the completeness of the esterification and trans esterification reactions. The copolyesters exhibited characteristic peaks at 3066, 2926, 2855 cm^(-1)(C-H stretching), 1708 cm^(-1)(C=O stretching) and 1608, 1559 cm^(-1)(aromatic). The ratio of absorbance of aromatic peak at 1608 cm^(-1) to that of C=O peak at 1708 cm^(-1) of the copolyesters increased with the increasing molar content of dimethy1-4, 4'-bibenzoate. Thus, the IR spectrum can indicate the composition of the copolyesters qualitatively. The copolyesters were also characterized by 1H NMR. The polymer compositions of the copolyesters could be determined from NMR spectra. The sequence distribution of some copolyesters could be determined from NMR spectra. The copolyeters exhibit a degree of randomness of about 1 indicating that they are random copolymers.